1. Field of the Invention
The present invention relates to a polymer alloy of polybutadiene and other olefinic saturated or unsaturated thermoplastics.
2. Technology Review
U.S. Pat. No. 4,386,179 discloses block copolymers of the styrene-butadiene-styrene (SBS) type or the styrene-ethylene-butylene-styrene (SEBS) type which are mixed with silicone oil and mineral oil. These mixtures provide an easily workable starting material for the production of, for example, medical articles such as balloon or endotrachial catheters. The end product is highly elastic. The mixtures have the drawback in that their intended use is limited to certain fields. The mixtures cannot be used to produce tubes that conduct liquids such as medicinal fluids, blood, and fat-containing liquid foods because the liquids leach components such as mineral oil out of the tubes' starting materials and the conducted liquids are contaminated.
Mixtures of polybutadiene with block copolymers and wetting agents based on sulfur improve the mixtures' processibility in subsequent vulcanization. Additives of 5 to 30 weight percent polybutadiene are added to the block copolymers. A major drawback of these mixtures is that they can be used in neither medical applications nor in the food industry because of the wetting agents.
One known advantage of using polybutadiene instead of polyvinyl chloride (PVC) is that polybutadiene is free of softener and polyvinyl chloride (PVC) components, which avoids the problems of the decontamination of objects made of polybutadiene. Polybutadiene does not have any migrating components which could contaminate the material flowing through it. Also, polybutadiene products do not absorb active materials from medical preparations, and components of polybutadiene products are not leached out by fat containing media, such as blood, milk, and fat containing nutrient solutions. Polybutadiene products have a low specific weight with high inherent elasticity, so in this respect they are ideal for medical and food industry applications.
Polybutadiene products have the drawback of not being easily connected using adhesive and not being easily produced in special configurations. Polybutadiene products have low heat resistance which preclude their sterilization in hot steam, and have a poor capability to return to their original shape as compared to PVC products. Further, the surfaces of polybutadiene products are rough and unsuitable in medical and food industry applications.